A 22-year-old man is hypotensive and tachycardic after a shotgun wound to the left

shoulder. His blood pressure is initially 80/40 mm Hg. After initial fluid

resuscitation his blood pressure increases to 122/84 mm Hg. His heart rate is now

100 beats per minute and his respiratory rate is 28 breaths per minute. A tube

thoracostomy is performed for decreased left chest breath sounds with the return of

a small amount of blood and no air leak. After chest tube insertion, the most

appropriate n...